That's easy its pluto
None. Pluto-Charon was almost considered one in 2006, though that would be a dwarf double planet rather than a true double planet as Pluto is not a planet. In billions of years the Earth and Moon will be a double planet. Also, the question is non-sensical because if it was a double planet then they would both be planets... so there would be no moon. A planet would be considered a double planet with it's opposite planet, not moon.
When Pluto was still officially considered a "planet" in our solar system, it and it's moon Charon were considered by many to be a double planet system. Whenever a moon constitutes a considerable percentage of the host planet's mass, it may be considered a double planet system. For this reason, some consider the Earth and our moon to be a double planet system. Our system has by far the greatest planet to moon mass ratio; about 6:1. As for planets outside our solar system, I cannot say. Though there are many out there.
First of all, Pluto is not a planet. It was considered a double planet because its largest moon Charon is half its size.
Earth and the Moon.
It is a moon of the dwarf planet Pluto. They are so nearly the same size it could almost be called a double planet system
Some consider it to be a double planet or, more properly, a double dwarf planet. However it is currently not officially considered as such.
No, at least not by the proper definitions. There are some definitions that would classify it as such, though, since the sun has a stronger grip on the moon than the Earth does. In billions of years, the Earth-Moon barycenter will finally be outside the Earth's surface so at that time the Earth-Moon may officially be considered a double planet rather than a planet and moon.
The parent planet of a moon is the planet that the moon orbits around. For example, the parent planet of Earth's moon is Earth itself. Moons are natural satellites that orbit planets due to gravitational forces, with the parent planet being the primary celestial body that the moon is gravitationally bound to.
Within our own solar system, some view Pluto as being a double planet with it's moon Charon (which is half it's size).
It's not. Also Jupiter has more than one moon.
Twenty-one
Pluto